android通过BitmapFactory.decodeFile获取图片bitmap报内存溢出的解决办法

　　android通过BitmapFactory.decodeFile获取图片bitmap报内存溢出的解决办法

　　原方法：

    public static Bitmap getSmallBitmap(String filePath, int reqWidth, int reqHeight) {
        final BitmapFactory.Options options = new BitmapFactory.Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeFile(filePath, options);

        // Calculate inSampleSize
        options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);

        // Decode bitmap with inSampleSize set
        options.inJustDecodeBounds = false;

        return BitmapFactory.decodeFile(filePath, options);
    }

　　异常：

06-23 11:41:04.817 24959-24959/com.test.tax E/AndroidRuntime: FATAL EXCEPTION: main
                                                                Process: com.test.tax, PID: 24959
                                                                java.lang.OutOfMemoryError
                                                                    at android.graphics.BitmapFactory.nativeDecodeStream(Native Method)
                                                                    at android.graphics.BitmapFactory.decodeStreamInternal(BitmapFactory.java:623)
                                                                    at android.graphics.BitmapFactory.decodeStream(BitmapFactory.java:599)
                                                                    at android.graphics.BitmapFactory.decodeFile(BitmapFactory.java:378)
                                                                    at com.test.tax.utils.PictureUtils.getSmallBitmap(PictureUtils.java:138)
                                                                    at com.test.tax.utils.PictureUtils.bitmapToFile(PictureUtils.java:58)
                                                                    at com.test.tax.utils.localalbum.ui.LocalAlbum.onActivityResult(LocalAlbum.java:141)
                                                                    at android.app.Activity.dispatchActivityResult(Activity.java:5441)
                                                                    at android.app.ActivityThread.deliverResults(ActivityThread.java:3353)
                                                                    at android.app.ActivityThread.handleSendResult(ActivityThread.java:3400)
                                                                    at android.app.ActivityThread.access$1300(ActivityThread.java:141)
                                                                    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1250)
                                                                    at android.os.Handler.dispatchMessage(Handler.java:102)
                                                                    at android.os.Looper.loop(Looper.java:136)
                                                                    at android.app.ActivityThread.main(ActivityThread.java:5047)
                                                                    at java.lang.reflect.Method.invokeNative(Native Method)
                                                                    at java.lang.reflect.Method.invoke(Method.java:515)
                                                                    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
                                                                    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:609)
                                                                    at dalvik.system.NativeStart.main(Native Method)

　　解决办法：

　　通过设置BitmapFactory.Options属性解决

        options.inPreferredConfig = Bitmap.Config.RGB_565;
        options.inDither = true;

　　解决后的方法：

    public static Bitmap getSmallBitmap(String filePath, int reqWidth, int reqHeight) {
        final BitmapFactory.Options options = new BitmapFactory.Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeFile(filePath, options);

        // Calculate inSampleSize
        options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);

        // Decode bitmap with inSampleSize set
        options.inJustDecodeBounds = false;
        //避免出现内存溢出的情况，进行相应的属性设置。
        options.inPreferredConfig = Bitmap.Config.RGB_565;
        options.inDither = true;

        return BitmapFactory.decodeFile(filePath, options);
    }